Permafrost Beneath the Beaufort Sea: Near Prudhoe Bay, Alaska

1980 ◽  
Vol 102 (1) ◽  
pp. 35-48 ◽  
Author(s):  
P. V. Sellmann ◽  
E. J. Chamberlain

The occurrence and properties of subsea permafrost near Prudhoe Bay, Alaska, were investigated by drilling and probing. Nine holes were drilled and 27 sites were probed with a cone penetrometer. The deepest drill hole was 65.1 m below the seabed, while a depth of 14.1 m was reached with the cone penetrometer. Engineering and chemical properties were determined from core samples and point penetration resistance data were obtained with the penetrometer. Thermal profiles were acquired at both the drill and probe sites. Temperatures below 0° C were observed in all the drill and penetrometer holes logged, although frozen sediments were encountered only occasionally. Seasonally frozen sediments were observed near the seabed at each site. The degree of ice bonding, or strength, could be related to seabed temperature and was greatest in shallow water (<2 m). The penetrometer resistance and thermal data indicated that deeper ice-bonded sediments occur, for example approximately 12.7 m below the seabed in 2 m of water off the Sagavanirktok delta. Of eight holes drilled offshore, it appeared that four encountered bonded permafrost. In general, the position of the ice-bonded permafrost interface was extremely irregular. The depth below the seabed to this interface at various distances from shore along the line studied was 28.8 m at 1 km, 65.1 m at 3.5 km, 44.1 m at 6.8 km, and 29.5 m at 17.2 km. Shallow, over-consolidated marine sediments were found in the upper fine-grained section at all of the drill sites investigated; the degree of over-consolidation varied considerably among the sites. This fine-grained section was up to 10 m thick and covered sands and coarse gravels.

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 565 ◽  
Author(s):  
C. D. Grant ◽  
D. A. Angers ◽  
R. S. Murray ◽  
M. H. Chantigny ◽  
U. Hasanah

Aggregate coalescence in irrigated cracking clays constrains crop yields, yet little is known about it or how it can be managed. A measure of coalescence is introduced to separate the effects of natural aggregate-bed densification from those of age-hardening; this measure, χ, comprises a ratio of the net change in (tensile or penetrometer) strength, Y, that occurs in relation to the corresponding net change in dry bulk density, ρb, as follows: χ = ΔY/Δρb. A laboratory study was conducted to illustrate the variation in χ for a virgin and cultivated cracking clay exposed to 16 weekly cycles of wetting and draining. Penetrometer resistance and tensile strength at –100 kPa, plus bulk density and other physical and chemical properties, were measured throughout the experiment. The cultivated soil rapidly became denser and stronger, it developed larger aggregates, and its water-uptake rate in the air-dry state was significantly greater than that for the virgin soil. The &chi; values suggested that age-hardening processes constituted a greater component of coalescence in the cultivated soil than it did in the virgin one, and this was thought to be mediated by the large differences in the content and composition of organic matter in the two soils.


2018 ◽  
Vol 37 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Rayko Simura ◽  
Tetsuo Taniuchi ◽  
Kazumasa Sugiyama ◽  
Tsuguo Fukuda

AbstractCe-doped YAG/Al2O3 melt-growth composite (MGC) samples were grown by the micro-pulling-down (μ-PD) method, and their physical and chemical properties were investigated. The grown MGC samples exhibit fine-grained granophyric texture at the micron scale. Fluorescence spectra, excited by a blue laser diode, were recorded, and, in particular, the finely textured granophyric MGC sample doped with 0.1 at% Ce and prepared with a growth rate of 3 mm/min shows superior fluorescence properties without high-temperature deterioration of fluorescence intensity. The μ-PD method is demonstrated to be applicable for manufacturing finely textured MGC samples with improved luminous efficiency as phosphors for white LEDs.


Author(s):  
A. Е. Аnikin ◽  
G. V. Galevsky ◽  
V. V. Rudneva

Results of studies of physical and chemical properties of rolling scale and dewatered sludge from gas-cleaning system of BOF plant quoted, carried out for estimation of technological advisability of application them in metallization processes. The studies carried out by application of standard methodics of determination of chemical, phase, grain-sized contents and density of fine and powder materials. It was determined, that content of total iron, FeO and Fe2O3oxides, Sulphur and Phosphor in the scale makes figures 73.3, 75.5, 20.9, 0.036 and 0.019 % correspondently, in the sludge – 41.2, 4.7, 53.7, 0.21 and 0.15 % correspondently. The sludge contains also up to 20.9% of CAO and 4.3% of total carbon. Grain-size contents of the scale and the sludge are considerably different: content of size grade +1.0 mm and –0.016 mm is in the scale 63.3% and 0%, in the sludge – 14.8 and 44.5 % correspondently. Real density of the scale is 4.6–4.9 g/sm3. The results obtained confirm a technological advisability of application of fine-grained scale and powdered sludge in metallization processes, including their preliminary briquetting comprising carbonic reduction agent.


1979 ◽  
Vol 1 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Scott E. Blouin ◽  
Edwin J. Chamberlain ◽  
Paul V. Sellmann ◽  
Donald E. Garfield

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.


1976 ◽  
Vol 73 ◽  
pp. 351-355 ◽  
Author(s):  
Gilles Goujon ◽  
Boyan Mutaftschiev

2015 ◽  
Vol 2 (2) ◽  
pp. 148-158
Author(s):  
Surianto

Spodosol soil of Typic Placorthod sub-group of East Barito District is one of the problem soils with the presence of hardpan layer, low fertility, low water holding capacity, acid reaction and it is not suitable for oil palm cultivation without any properly specific management of land preparation and implemented best agronomic practices. A study was carried out to evaluate the soil characteristic of a big hole (A profile) and no big hole (B profile) system and comparative oil palm productivity among two planting systems. This study was conducted in Spodosol soil at oil palm plantation (coordinate X = 0281843 and Y = 9764116), East Barito District, Central Kalimantan Province on February 2014, by surveying of placic and ortstein depth and observing soil texture and chemical properties of 2 (two) oil palm's soil profiles that have been planted in five years. Big hole system of commercial oil palm field planting on the Spodosol soil area was designed for the specific purpose of minimizing the potential of a negative effect of shallow effective planting depth for oil palms growing due to the hardpan layer (placic and ortstein) presence as deep as 0.25 - 0.50 m. The big hole system is a planting hole type which was vertical-sided with 2.00 m x 1.50 m on top and bottom side and 3.00 m depth meanwhile the 2:1 drain was vertical-sided also with 1.50 m depth and 300 m length. Oil palm production was recorded from the year 2012 up to 2014. Results indicated that the fractions both big hole profile (A profile) and no big hole profile (B profile) were dominated by sands ranged from 60% to 92% and the highest sands content of non-big hole soil profile were found in A and E horizons (92%). Better distribution of sand and clay fractions content in between layers of big hole soil profiles of A profile sample is more uniform compared to the B profile sample. The mechanical holing and material mixing of soil materials of A soil profile among the upper and lower horizons i.e. A, E, B and C horizons before planting that resulted a better distribution of both soil texture (sands and clay) and chemical properties such as acidity value (pH), C-organic, N, C/N ratio, CEC, P-available and Exchangeable Bases. Investigation showed that exchangeable cations (Ca, Mg, K), were very low in soil layers (A profile) and horizons (B profile) investigated. The low exchangeable cations due to highly leached of bases to the lower layers and horizons. Besides, the palm which was planted on the big hole system showed good adaptation and response positively by growing well of tertiary and quaternary roots that the roots were penetrable into deeper rooting zone as much as >1.00 m depth. The roots can grow well and penetrate much deeper in A profile compared to the undisturbed hardpan layer (B profile). The FFB (fresh fruit bunches) production of the non-big hole block was higher than the big hole block for the first three years of production. This might be due to the high variation of monthly rainfall in-between years of observation from 2009 to 2014. Therefore, the hardness of placic and ortstein as unpenetrable agents by roots and water to prevent water loss and retain the water in the rhizosphere especially in the drier weather. In the high rainfall condition, the 2:1 drain to prevent water saturation in the oil palm rhizosphere by moving some water into the drain. Meanwhile, the disturbed soil horizon (big hole area) was drier than un disturbance immediately due to water removal to deeper layers. We concluded that both big hole and 2:1 drain are a suitable technology for Spodosol soil land especially in preparing palms planting to minimize the negative effect of the hardpan layer for oil palm growth.


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